The present invention relates in general to the field of data input devices, and particularly to a generalized character input interface for compact electronic devices requiring alpha-numeric inputs from the user.
As electronic devices, such as personal digital assistants (PDAs) continue to decrease in size, proper design of the input interface for these devices becomes more important. As the space required for implementing the input interface becomes increasingly more limited, an improper design of this interface may render the electronic devices cumbersome, slow, or even unusable. For example, too many buttons on the interface may disorient an unsophisticated user. Too few keys may require that the available buttons be assigned secondary or even tertiary functions, greatly increasing the number of keystrokes and time required for even simple entries. A cumbersome layout would render the data entry slow and tedious, while tiny keys or buttons would be difficult to see and manipulate and, in addition, would require extreme precision on the part of the user.
Current personal digital assistants have mitigated these problems by incorporating a scheme that allows menu and other selections to be made by touching sensitive areas of the screen. In addition, many devices allow alphanumeric character input by means a stylus that is used to xe2x80x9cwritexe2x80x9d on a touch-sensitive portion of the screen. The electronic device is then capable of translating the handwriting using a simplified handwriting-recognition algorithm.
These interfaces, while functional, might not represent an optimal solution that adequately addresses the rapid input of alphanumeric and other data input in miniaturized electronic devices. The need for such an input interface has heretofore remained unsatisfied.
An attribute of the present invention is to provide a rotary interface for inputting text and other information into a small electronic device. In particular, this invention allows the user to quickly select and input large amounts of textual information into very small devices such as cell phones, hand-held or watch-sized PDAs, or other small devices with embedded processors where standard keyboard entry is untenable and where menu-driven selection and handwriting recognition-based character entry are non-optimal.
The foregoing and other features and advantages of the present invention are realized by an interface where alpha-numeric characters or other options, such as icons, are arranged in an optimal fashion on a physical or virtual ring or dial that can be rotated, either physically or electronically, in both a clockwise and counter-clockwise direction. The input interface is further equipped with a means of unambiguously selecting and then easily inputting the designated character into the memory of the electronic device.
The method of choosing and entering characters with a dial mechanism is particularly well-suited for inputting text in constrained contexts. An exemplary case is one of a dictionary application being executed on a watch-like electronic device. The user, using the dial and selection mechanism can rapidly enter letter into the electronic dictionary without pushing small, individual key.
A feature of the present interface is its dial layout or arrangement that allows the character of choice to be reached quickly, with bi-directional rotation. This layout ensures that, in certain embodiments, no character is more than 180 degrees from the previous selection point.
Optimal arrangement of the characters allows the user to easily and logically choose the next xe2x80x9cvaluexe2x80x9d in the input sequence. Depending on implementation details, as determined and required by the size, shape and function of the electronic device, the rotation of the dial may be achieved either with a physical/mechanical twist or rotation by the user, or by using directional electrical/electronic switches or buttons. In certain embodiments, the user may be given the option of using either the dial or the electronic switches.
Depending on the application, the characters or icons may be permanently affixed on a mechanical ring or may be displayed around the periphery of an electronic display in an arrangement customized to the task and/or possibly determined by the habits or preferences of the user. In the case of the mechanical dial, the character set is fixed at the time of manufacture. The orientation of the characters is such that they are most easily read by the user when rotated into a position for selection, typically the 12 o""clock position. Characters are selected by rotating the ring or dial in a fashion similar to that used in a combination lock.
In other embodiments, the characters are not physically imprinted on the dial mechanism, rather the dial mechanism includes a rotary display on which the characters are displayed. In these embodiments, the dial mechanism can be programmed to display the desired characters or icons. In the case of the electronic character display, the rotatable ring or dial is made separate, distinct and is unmarked. Thus, the ring or dial is simply used to scroll through and then select a specific character from a list of available inputs which are displayed on an electronic screen.
The use of the electronic display makes the character orientation significantly more versatile than the mechanical inscriptions. Consequently, each character""s orientation may change for maximum legibility/readability each time the ring of characters is rotated, thus, remaining in a 12 o""clock orientation. Furthermore, characters available for selection may change according to the specific task at hand. For example, characters could be displayed on the electronic screen in any of a number of alphabet types such Roman, Arabic, Hebrew, or Cyrillic or be converted to any number of icons, numbers, etc.
A number of options are available for entering the character or icon of choice. One, which is an analog of a dial on a combination lock, allows a symbol to be entered by simply changing the direction of rotation once the character of choice has been reached. Another option is to use a button or xe2x80x9center keyxe2x80x9d to signal to the electronic device that the target character has been aligned with a reference location and that the chosen character should be input into device memory.
In neither type of character entry is there a requirement that a button or key associated with a specific letter, character or icon be depressed or pushed with a finger, stylus or other tool. While the characters can be sized for legibility as well as appropriately sized to the electronic device, the selection and entry elements can be made compatible with human manipulation.
Thus, in its most basic form, the input interface comprises three main components: (1) a rotatable character or icon display in the form of a dial, a ring or appropriate electronic display; (2) a means of unambiguously displaying or designating the currently selected character; and (3) an entry mechanism for inputting the character data into the memory of the electronic device. A fourth element, a display of previously entered characters, aids in operation but is considered optional.
A number of options are available for the implementation each of these main components. Specifically, the character or icon display may be a manually or electronically rotatable ring, dial or electronic display. This may be extended to a plurality of rings, depending on the required functionality. The character selector/designator may be a simple, scribed mark on the device or an electronic display.
According to one embodiment, the entry mechanism is the reversal of the rotation direction of the ring after reaching the character of choice, in analogy with a combination lock. According to another embodiment, the character of choice is input with an xe2x80x9center key.xe2x80x9d In both embodiments the character to be entered is designated unambiguously by either the alignment marker or the selection display.
The rotational character entry device of the present invention distinguishes itself over conventional devices for alpha-numeric character entry for small electronic devices by its simplicity, ease of use, efficiency, and versatility. It can be easily adapted for use in most electrical and electronic control systems where small size limits the effectiveness of conventional character-entry schemes such as miniature keyboards, character recognition and menu-based systems.